Photographic printing machine



Oct. 29, 1935. 5 HOWELL 2,019,260

PHOTOGRAPHIC PRINTI NG MACHINE Original Filed June 16. 1930 6 Sheets-Sheet 1 Oct. 29, 1935. A. s. HOWELL PHOTOGRAPHIC PRINTING MACHINE Originai Filed June 16, 1930 6 Sheets-Sheet 2 Oct. 29, 1935. A s, HOWE L 2,019,260

PHOTOGRAPHIC PRINTING MACHINE Original Filed Jfine 16, .1930 6 Sheets-Sheet 3 M12707? QlberfSHayell y 42 Oct. 29, 1935. A. s. HOWELL 2,019,260

PHOTOGRAPHIC PRINTING MACHINE Original Filed June 16, 1930 6 sh ets sfieet ,4 1

w IQL/ Ill w ,2 ZZZ d/berz 3 How/l Oct. 29, 1935.

A. S. HOWELL PHOTOGRAPHIC PRINTING MACHINE Original Filed June 16. 1930 6 Sheets-Sheet 5 Oct. 29, 1935 A. 5. HOWELL PHOTOGRAPHIC PRINTING MACHINE Original Filed June 16, 1930 6 Sheets-Sheet 6 w wlfii t l I.

Patented Oct. 29, 1935 PATENT OFFICE PHOTOGRAPHIC PRINTING MACHINE Albert S. Howell, Chicago, 111., assignor' to The Bell 85 Howell Company, Chicago, 111., a corporation of Illinois Application June 16, 1930, Serial No. 461,331 Renewed April 1, 1935 25 Claims.

My invention relates particularly to motion picture film printing machines, although not limited to this use alone.

The general object of my invention resides in the provision of an eflicient and improved photographic printing machine of the progressive printing type, such as is used in the printing of motion picture films, having a novel and effective .printing light control, and preferably providing for the printing of picture and sound records upon a film from separate picture and sound record bearing printing films, all with a view toward convenience. automatic operation and reduction of supervision during printing. and high production.

With this object in view my invention consists in certain features of novelty in the construction, combination, and arrangement of parts by which the said object and certain other obiects, hereinafter appearing, are effected, all as fully describedwith reference to the accompanying drawings and more particularly pointed out in the appended claims.

In the said drawings- Figure 1 is a partial front elevation of a motion picture film printing machine embodying my invention;

Figure 2 is a partial rear elevation of the same with parts removed, broken away and shown in section;

Figure 3 is an enlarged partial section on the line 3-4 of Figure l;

Figure 4 is an enlarged partial section on the line 4-4 of Figure 3;

Figure 5 is a'partial top plan view of the machine;

Figure 6 is a partial section on the line 6-8 of Figure 5;

Figure 7 is a partial section on the line 1-7 of Figure 5;

-Figure12;

Figure 14 is a face view of a portion of a film printed in the machine;

Figure 15 is a longitudinally condensed face view of a portion of a light control film, hereinafter described, used in the machine; and 5 Figure 16 is a partial transverse view of a portion of one of the film feed rollers of the machine and its cooperating control roller, hereinafter described.

Like characters of reference indicate like parts s in the several views.

Referring to the drawings, I designates the frame of the machine, which is of generally flat horizontally elongated form and which is disposed vertically. See Figures 1 and 2.

Arranged along the back of the frame I adjacent the top thereof is a horizontal drive shaft 2 journaled at spaced points on the frame, and mounted on the frame at one end thereof'is an electric motor 3 which drives the shaft through suitable spiral gearing 4.

Two of exposure devices, generally designated at 5 in Figure l, are carried on the frame I adiacent the top thereof and are spaced along the drive shaft.

Inasmuch as, except as hereinafter described, these exposure devices are identical but one of them will be described, it being understood that such description applies to both, in accordance with which the same reference characters are 80 applied similarly on the drawings.

Each exposure device consists as follows. Mounted in a bore through the frame I is a generally cylindrical member Ii disposed on an axis normal to that of the drive shaft 2 and dis- 8!! posed below the same. Formed on the front of the frame I is a hollow cylindrical enclosure for-- mation I, the front side of which is closed by a removable cover 8. See Figures 3 and 4.

Arranged in this enclosure and disposed con- 40 centrically therewith is a film sprocket comprising axially spaced sprocket wheels 9, and a small axial shaft III, extending therebetween.

This sprocket is provided with a rearwardly extending shaft II iournaled in the formation Ii coaxially therewith, which shaft projects rearwardly and has secured on its rear end a worm gear wheel I2 meshing with a worm gear I3 secured on the drive shaft 2, whereby the sprocket including the sprocket wheels 9 is driven to from the drive shaft. I

The front portion of the enclosure formation I in which lies the aforesaid sprocket forms a light chamber and arranged at the top thereof is an exposure film guide disposed horizontally and exl6 tendingincowiththedriveshaft2, whichguideisconstructedasfdlm,

Intheplsneofthesprocketthewalloftbeenclosure formation 1 is cut away at its top portion, 5 anddisposedbetweenthesprochetwheelstwitm in the enclosure formation aretwoarcal members II, which are secured outwardly against the formation I and which.exceptashereinafterdescribedareseparatedattheupperendsthereof mtoformanexposureaperturad at Ii inl'lgure4.

Theimperendportionsofthesearcalmembers adjoining the exposure apertm'e Ii. in coniunction with straight guidemembers it forman upwardlyfacingfilmfaceguidenn'facathecenterportionofwhichembracestheexposureapertune liandiscurvedtocoincidew'iththepitch' motionjaicturefilmfiengagedthereininsuperposed printing relationand engaged by the aforesaid sprocket for the feeding of the films-.in

prmtingrelationthmughthe guidetoprogresslvelyprintthepositivefilmfromthenegativefiim dmbymeans ofprinting lightthroughthe exposure aperture II to the films.

. Thegatemember-ltispivotedonthestudll for-movementfromfilmguidingorretainingpositionupwardlytoapositioninwhichtheguideis i5- openforthelacmgandimlacingofthe'filmsinthe guide, andtheclosed position of theguide memberisdeterminedbyastopflontheframelem gagedbyascrewflscrew-threaded throughthe freeendofthegatememberandsecuredinadso: justedposltionhyalocknutii. BeeFigurei.

Theprlnting lightisprovided for'the expome device in the following manner. Bee Figures 3 andd. Iniheplaneofthesprocketthewallofthe flformation'lisalsocutaway atit'slowerportion andthearcsl llhavethelowerends thereof separatedtoformalight apertin'e, designatedat 26inFlgure4,andsecuredcntheenclosurelandhavingtheiradiaeentendsspacedin registrywiththe taperturefiarefilmface guide members 21 having their lower guide surfacesdisposedtangenidallytoacirclecoaxialwith the aforesaid sprocket and adiaeently spaced outwardlyfromtheteeththereof.

Pivotedonastudfisecuredmtheframeiin parallelismwiththeaforesaidsprocketisasec-' ondgate member 29,theupper-surfaceofwhich.

isfacedbyafilmface guide member" curved to conform with the aforementioned circle and theguide members 21, thus forming a film guide outwardly adjacent the teeth of the aforesaid sprocketandspacedhelowandextendingcorrewith the aforesaid exposure guide. The gate member 29 is hollow, as hereinafter deeeribedandtheguidememberll isprov'ldedwith 1mm. through the 1m described. film guide, be-

tween the sprocket wheels 8 and through the exposure aperture IE to the superposed negative and pomtive films 2| and 22 for the printing of the positive film. p

The gate member 29, as aforesaid is hollow and provides an angled light passage 28 continuing the 19 light aperture of the guide including this gate memberandterminating atarearface ,ofthe gate member. disposed normal to the pivotal axis thereof and slidably engag ng an opposing face 25 of the frame I. The frame I is provided with is a light e 26 terminating at the face 38 thereof which continues the light passage of the gate member 28 and communicates with a lamp chamber Il-on the rear of theframe in which is arranged a suitable incandescent electric lamp 28 no providing printing light.

Mounted on the gate member 22 at the angle of flielightpassageltthereofisarefiectingprism 2. which reflects light from the lamp upwardly through the light aperture 26 of the lower film 28 guideandbetweenthesprocket wheels! tothe exposure aperture Ii of the upper or exposure guide for the printing of the positive film 2| from the negative film 22in the upper guide. A con- .densinglens ismotmtedonthegatememberfl so adjacent the lower film guide and lies across the light passage 22 for concentrating the light.

The gate member 29 is pivoted on the stud 22 for. movement iromfilm guiding or retaining pofltion downwardly to a position in which its as guide is open for the lacing and unlaeing of a light control film 42, hereinafter described, in this guide, a spring 12, see Figure I. normally positioning this gate member in film guiding or retaining position as shown in the drawings. 40

As before stated. the machine involves two such expomre devices spaced along the drive shaft 2, the purpose of the two exposure devices being the simultaneous printing of related picture and soimd records upon the positive film 2i, from separate picture and sound record bearing negative films, along adjoining longitudinally extending sections thereof, as shown in Figure 14 in which the picture section is indicated at 44 and the soimd-section at l5. l0

- Accordingly. these exposure devices differ in respect to the'exposure apertures of their expowre gu'ides'as follows.

The picture record exposure device is at the right in Figure 1 and'is shown inFig'mesll vice. disposed at the left in Figure 1,-has one of 65 the arcal members It thereof provided with an extension similarto the extension 45 but registering with the picture record section 44 of the positive film whereby only the sound record section is exposed in the sound record exposure device. 10 Of the films aforementioned, only the positive film 2| is fer through the second or sound record expowre device, a second printing or negative sound record bearing motion picture film 41 being fed in printing relation with the positive film fl 2,019,260 through the sound record exposure device. Bee

Figure 1. A second ligh't control film 48 is fed through the lower film guide of the soimd record exposure device for controlling the exposure of the sound record section 45 of the positive film therein. the light control film 42 in the lower film guide of the picture record exposure device con trolling the exposure of the picture record section 44 'of the positive film therein.

The several films are carried and fed to and from the said exposure devices in the following manner. See Figure 1.

Extending upwardly from the intermediate portion of the frame I are two arms 49 and mounted on the upper ends of these arms are two horizontallyspacedfilmspoolsil carryingthewound portions of the positive film 2|.-

Fromtherighthandspool Sl'thefilm2l leads to and is engaged on a constant feed sprocket 52 at the right of the machine, and from thence leads through a film tensioning device 53 to the right end of the exposure guide of the picture exposure device. From the left end of the picture exposure device this film leads through mother tensioning device 54 to andis engaged on a constant feed sprocket 55 disposed above and intermediate the exposure devices. From the sprocket this film leads over a guide roller 55 and then throughja film tensioning device 51 to the right end of the exposure guide of. the sound exposure device. From the left end of the exposure guide of the sound exposure device this film leads through a tensioning device it and about a constant feed sprocket 58 at the left of the machine to the left hand spool 5L.

If it is desired only to print the positive film in the picture exposure device,,as where it is only desired to print a picture record on the film, the filmmay beled directlytothelefthandspoolii from the guide roller 55, as indicated at 6|.

Two downwardly disposed horizontally spaced filmspools I. are mountedonthefrarne l below the right hand or picture exposure device and these spools carry the wound portions of the picture record hearing or negative film 22.

From the right hand spool t2 the film 22 leads upwardly to and about a constant feed sprocket 63 atthe right of the machine, and from. thence leads through a film tensionlng device 64 to the right end of the 'exposure'guide'of the picture exposure device. From the left end of the exposure guide of the picture exposure device this film leadsithrough another tensloning device 65 to and over a constant feed sprocket 66', and from this sprocket this film leads downwardly to the left hand spool 62.

Two downwardly disposed horizontally spaced film spools l are mounted on the frame 1 below the left hand or sound exposure device and these spools carry the wound portions of the'soimd record bearing or negative film 41.

From the right hand spool l the film 41 leads upwardly to and about a constant feed sprocket 68. and from thence leads through a film tensloning device it to the right end of the exposure guide of the sound'exposuredevice. From the left end of the exposure guide of the sound exposure device this film leads through another tensioning, device If to and over a constant feed sprocket l2, and from this sprocket this film leads downwardly to the left hand spool 61.

The sprockets t3, t6, 6! and I2, spaced along the driveshaft 2, are driven from this shaft by means of spiral gearing It correspondingly spaced 'alongtheshaft. SeeFiguresIandiI The sprockets 52, '55 and it are disposed immediately above the sprockets 63, 68 and I2 and are driventherewith by means of spur-gearings 14, all of these sprockets being thus driven in unison with the sprockets formed by the spaced ii sprocket wheels 9 for feeding the films 2|, 22 and 41 to and from theexposure guides.

For purposes hereinafter described the light control films 42 and 48 are fed through the lower guides of the exposure devices in correspondence with the feed of the films 2|, 22 and 41. but. as shown. at a slower speed. Accordingly, the length of the films 42 and 48 cor.- responds with but is correspondingly shorter than that of the films 2|, 22 and 41,-and the l5 films 42 and 48 are carried and fed to, from and through the lower guides of the exposure devices in the following manner.

Two downwardly disposed horizontally spaced film spools 75 are mounted on the frame I below the right hand or picture exposure device and immediately above the spools 62, and these spools I5 carry-the wound portions of the picture light control film 42.

From the right hand spool 15 the film 42 leads over a constant feed sprocket It to the right end of the lower film guide of the right hand or picture exposure device. From the left end of the lower film guide 'of the picture exposure de vice this film leads over another constant feed sprocket TI to the left hand film spool It. Two downwardly disposed horizontally spaced film spools 18 are mounted on the frame I below the left hand or sound exposure device and immediately above the spools 61, and these spools I8 carry the wound portions of the sound light control film 48.

From the right hand spool 18 the film 4! leads over a constant feed sprocket Iii to the right end of the lower film guide-of the left hand or sound exposure device. From the left end of the lower film guide of the sound exposure device'this film leads over another constant feed sprocket II to the left hand film spool 18. j

The sprocket 16, I1, 18 and Bi, spaced along the drive shaft hare driven from this shaft to feed the light control films 42 and 41 in correspondence with the positive and negative films by means of vertical shaft and-spiral gearing mechanisms correspondingly spaced along the shaft and generally indicated at 82 in Figure 2.

The machine is adapted for printing in either direction of feed of the films, as will be hereinafter more fully referred to, and for this purpose the following drives for the ,film spools are provided. I

The shaft of the sprocket has secured thereon a double grooved pulley It, and the shafts of the spools 6| have rotatably mounted thereon pulleys 84 which are driven by means of belts I! w trained thereabout and about the pulley It. The pulleys 84 are operatively connected with the spools SI by automatic one way drivi g connections, hereinafter described, arranged so that film fed to either of these spools, depending upon the direction in which the machine is operated.

' will be wound thereon while the film will be perand about'the adjacent pulleys I4. The pulleys u Eng gig.

- I and 10 have rotatthereon grooved pulleys which cans of belts 0| trained theret the adjacent pulleys 01. The

iii

will permittedtohe The aforementioned automatic one way driv-- ing connections will now be described with referencetooneoi thespoolsflandthepuiieyll thereof. it being understood that the description is applicableto all'such devices. Bee Figures 12 andl8 "lhespooltlissecuredonasbaftliwhichextendsthroughandisiournaiedinaborethrough I, and the pulley I1 is rotatably so mountedon-therearendofthissbaft. Secured ontheahaftinwardlyadjacentthepulleyisa dhkliprovldedwithspacedperipheralcamreeessesflmndthepulieyisprovidedwithacrlim dricalfiange lisurroundingthedisk. as lisposedintherecessesflareclutchballsll areretainedinangularspacedrelation by a llloosewithreferencetoboththepulley shaft, thiscage cooperating with a the llonthcshaftforretainingtheballs 'lheeamrecessesltarsoi'ormedthatwhen ,the Iris rotated in one direction, 1. e., eloetwiseinl'igurelihthebailsflarewedged between thedisk l3 and the flange]! toestabdriving connection. when, however, the pulley 01 is rotated in theopposite direction the larefreefromsuchwedgingactionwith the result thatthe pulley ll rotates independentlyottheshaftflandspooltl forthedrawing olfilmfrcm'thespool. v

'llielight controlfilmsfl and 40 ,throughwhich printing l t passes in exposing the positive bysaidexposuredevices,itwillbeobserved, aretedin'synchronismwith-the negative andposas Itivefilms in either direction of operation of the consist as follows. See Figure 15 showing a portionofthefilmfl whichdiffersfromthefilmll orothersuchlishtcontrol filmsonlyinsofar l y p tosraphically produced. and of individually preselected different extents for varying the exposure oiithe corresponding sections of the posg itivc film as the light control. negative and posi-' tive filmsareted through thcirexposuredcvicc' in synchronism.

'lhe sections 00 of the light control film correspond in length with the length of the corresponding sections or scenes of the negative film 5 and the densities thereof are selected with due regard to Ihe densities of the corresponding sectionsorscenes otthe negativefilm,sothat asa section of the negative film passes through the exposure device during the printing operation the corresponding section of the control film is passing through the lower guide of the exposure device for giving the corresponding section of the positive film the proper or desired exposure.

The light control strip, if motion picture film. may be a one-piece strip pon which the several sections of difierent densities have been photographically produced thereon, or may be made of strips of different densities photographically produced. assembled by splices I00, in which case go the sections of difi'erent densities may be cut from a stock of rolls of developed film, each having a diiferent density throughout and graded to standard densities.

In mounting a negative film and its light controi film on the machine it is only necessary that these films-be properly timed after which the change of the control of the exposure light is automatic and requires no further attention on the part of the operator. 0

As before described, the machine is adapted to operate in either direction. and it will be observed that the light control film as driven in correspond-- ence with the negative and positive films automatically controls or varies the printing lighf during the printing operation and provides the same exposure at corresponding sections of the negative film irrespective of thedirection of feed of the negative and positive films.

In order .to effect operation or the machine in either direction a conventional reversing switch IN is connected in circuit with the motor 3. See I Figures 5 and i1.

In order to interrupt operation of the machine in either direction at the end of a predetermined run thereof the following is provided. See Figures 2 and 5.

Disposed at the top of the frame I in parallelism with the drive shaft 2 is a screwthreaded shaft I02 which is rotatabiy mounted in spaced bearings I03 and which is driven from the shaft 2 by means of a spiral gear drive. generally indicated at I04.

Mounted on the bearings I03 for longitudinal movement is a bar I05 disposed in parallelism with the shaft I02, the movement of the bar being limited by pins I06 in the bar and engaging the bearings I03. Screwthreaded upon the shaft I02 is a nut member IOI-which is provided with a bifurcated projection I08 embracing the bar I05 and slidable therealong.

'ihebar I0! is provided with a series of notches I09 therealong in which are selectively engaged. for the adjustable positioning along the bar of two U-shaped stop members III between which 5 the projection I08 is disposed and which are engageable thereby for longitudinally operating the bar with opposite movements of the nut member effected by rotation of the shaft I02 in its screwthreaded engagement with the nut member See Figures Sand 7. I

Connected in circuit with the motor I to con.- trol operation of the machine is an electric switch carried on one of the bearings I 03 and comprising a stationary contact H2 and a cooperating rotatably fixed with the collar.

movable contact I I3 carried on one arm of a pivoted bell crank II4. See Figures 5 and 11. The bell crank is yieldably urged into open circuit position by a spring H5 but is normally maintained in closed circuit position by engagement of the. other arm of the bell crank lever with a side of the bar I85. This side of the bar I05 is provided with a notch II5 into which the said other arm of the bell crank lever moves when the bar is in an intermediate position of its movement to open the switch and stop operation of the machine.

The operation of this device is as follows. When the machine is started the stop members III are adjustably positioned on the bar I05 to correspond with the desired run of the machine, and the bar is positioned at the end of its movement opposite that in which the nut member Itl will move upon operation of the machine in the desired direction.

As the machine is operated the nut member I51 approaches the corresponding stop member III, and, adjacent the end of the predetermined run of the machine, the projection I08 of the nut member engages the corresponding stop member II-I and with continued movement of the nut member operates the bar to its intermediate positlon in which the bell crank lever engages the notch I I5 of the bar and opens its switch, thereby stopping operation of the machine.

'After operation of the machine is so stopped, the bar I05 is reset for stopping the machine in the opposite direction by moving the same to the end .of its movement opposite that in which the nut member I51 will travel during such operation of the machine.

The film tensioning mechanisms including the hereinbefore referred to tensioning devices 53, 54, 51, .58, 54, 55, 59 and II, operative upon the negative and positive films, are constructed and controlled asfollows.

Slidably mounted for limited movement in suitable bearings on .the frame I and disposed in adiacent parallelism with the drive shaft 2, is a rod 1, the intermediate bearing of which is provided with a spring pressed latch lever H8 engageable in any of three circumferential grooves H5 on the rod for-positioning the rod in any of three positions thereof for purposes to be described, and the rod has secured thereon an upwardly projecting handle I2I for the convenient manual positioning of the rod. See Figure 2.

Theaforesaid tensioning devices are spaced along the rod III and each consists as follows. See Figures 8, 9 and 10.

A shaft I22 extends through and is pivotally engaged in a bore through the frame I. See Figure 9. Rotatably mounted on the front end of this shaft is a film roller I23, and secured on the shaft between this roller and the frame is a roller arm I24 upon the free end of which as a second revoluble film roller I25 is mounted.

A film is reversely laced on these rollers, see Figure 1, so that movement of the arm I24 to engage the roller I25 against the film eifects a tension of the film between the corresponding sprocket formed by the sprocket wheels 9 and the corresponding sprockets 52, 55, 59, 58, 55,58, or I2.

Pivoted on the shaft I22 at the rear of the frame I is a collar I25 and engaged in a rearwardly facing bore in this collar and encircling the shaft is a torsion spring I21 the inner end of which is .See Figures 9 and 10. The outer end of this spring is engaged 'with a radially extending pin I28 mounted on the rear end of the shaft I22, thus forming a torsional spring connection between the shaft and collar, the relative movement of the shaft and collar under the influence of the spring being limited by an axial extending pin I28 on the 5 collar and engaged by the pin I28. See Figure 10.

Assuming that a film is laced on the rollers I23 and I 25 as before described, the relation is such that angular movement of the collar to separate the pins I28 and I29,'clockwise in Figure 10, tends to move the roller I25 against the film and, such movement of this roller and the arm I24 and shaft I22 being opposed by the film, the pin I29 disengages from the pin I28, thus causing the spring I21 to operate on the shaft,- arm and roller I25 to yieldably urge the roller against the film to provide a spring pressed or yieldable tension on the film.

Secured on the rod H1 at suitably spaced intervals are fingers I3I which are engageable with so crank fingers I32 on the dollars I for angularly controlling the collars. Thus, as a finger I 3i is moved against its crank finger I32 by longitudinal movement of the rod I II in the proper direction, the collar I25 is angularly positioned to resist 25 opposite movement of the arm I24 and its roller I25 through the spring I21, and movement of the rod in the opposite direction permits such opposite movement of the arm I24 and its roller I25.

The tensioning devices on opposite sides of each exposure device are oppositely arranged, see Figures l and 8, so that the tensioning devices on one side of the exposure device are alternately placed in film tensioning condition with opposite movements of the rod 1. Thus, when the rod 35' is positioned with the latch lever H8 engaging one end groove H9, see Figure 2, the tensioning devices on one side of the exposure devices are placed in film tensioning position while the tensioning devices on the other side thereof are not, 0 for the operation of the machine in the corresponding direction, and when the rod is positioned with the latch lever I I8 engaged in the opposite end groove II 9 the condition of the tensioning devices on opposite sides of the exposure devices 5 is reversed for the operation of the machine in' the opposite direction. Figure 8 illustrates the different positions of the arms I24 and rollers I25 of the tensioning devices associated with one of the exposure devices.

When the rod II! is positioned in its intermediate position with the intermediate groove II! thereof engaged by the latch lever 8, all of the tensioning devices are positioned in film lacing positions in which they serve to provide the proper lengths of film between the sprockets, the film lacing positions of the arms I24 and rollers I25 being substantially the same as the tensioning positions thereof, though in the film lacing positions the pins I28 and I29 are engaged while in the tensioning positions these pins are separated for tensioning action of the springs I21.

In order that the direction of operation of the machine and the film tensioning devices may be controlled together in correspondence, the movable member of the reversing switch IOI is provided with a bifurcated end I33 which embraces the handle I2I, see Figure 5, whereby the switch is operated with movement of the handle and its rod III, the arrangement being such that the tensioning devices are set for operation of the machine in the corresponding direction as determined by the position of the reversing switch at the opposite ends of the movement of the handle I2l and rod III. In the intermediate position of anotherarmI88andthlsarmisoperativelyconnected with a lever I". plvotally mounted on the resroftheframe Lby a connectinglink ill. See Figure 2. The lever I" is operatively conneeted witha weighiedmercuryswitch ll2,pivotallymountedontheframe Lbyaoonnecting link I43, so that upward movement of the plunger I" eifccted by opening movement of the gate member ll causes tilting of the switch I41, \gainstthe infiuenceoftheweightthereof.into

Slandthemotorlsothatwhenthegatememberilisopenedtheprinflng lightandoperation ofthemachinelsinterrupteduntilthegatememberis-closed.

'lheg'atememberlllsprovidedatitspivo hub with an areal formation I which is enare engaged by the negative films feed me; 0'1, a. a and 12. See Figure 1. a plurality of shafts m are pivotal]: moimted interrupt the printing l ght and stop operation ofthemachine.

Pivotaliymountedonthefmme I adiacentthe shaftsillarearmsluprovidedwithrollersifl attheirfreeendswhichareyieldablym-gedby springs liiagainstthen s tive mm a mu andtheiightconuolfiimsiiandllisttbc a,o1s,soo'

- guide rollers m and the ummed n, 11, II

and ii.

The arms I53 are provided with fingers I which engage fingers I51 secured on the shafts lil andwhile the rollers I54 engage filmonthe rollers I and the sprockets fit, 11, I! and II maintain the switches I52 in closed circuit position. thus permitting operation of the machine to print.

The rollers I are provided with spaced cir- 6 cumferential flanges I58 which engage against opposite margins of film on 'the rollers I or sprockets Ii, II, II and II, see Figure 16, and

these rollers and sprockets are provided with grooves I58 registering with the flanges III to 1| permit movement of the arms I53 under the in-- fluence of the springs to a position to tilt the switches in into open circuit positionvif film, is not interposed between the rollers Ill and the sprockets l8, I1, I! and II. 29

Thus upon breakage of any of the films 22. I1, 42 or 48 one of the arms I53 will move to a position to move its switch iii to open circuit position. thus interrupting-the printing light and stopping operation of the machine.

In the printing of a number of positive films from the same negative films, the negative films and their light control films are laced on the machine together with the first positive film to be printed. The stopping device is then set for 3 the required rim, andthe machine is set in operation which 'is continued until the positive film is printed and the machine stopped automatically.

Then the handle I2! is set in its neutral positioninwhichthetensioningdevicesareintheirgg lacing position and the printed positive is removed and a new unprinted positive is laced in the machine. After setting them I" for stopthe light control films. V

Itwill be observedthat'the arrangement of themaehineissuchthattheinterehangeofthe tive films is simple and convenient and a .welladapted fortheoperstionotthemachinein alternate directions with attendant advantages.

While I have described and shown the pre- 'ferredembodimentofmyinventionldonotwish and each of said control sections corresponding in extent with the corresponding scene or section of the printing element, and each section of said control element having a uniform exposure characteristic corresponding with the density of the corresponding scene or section of the printing element to effect the desired exposure of the sensitized element throughout its extent, and means for feeding said sensitized, printing and control strips in synchronism.

2. In a motion picture film printing machine the combination with an exposure guide adapted for the passage of superposed printing and sensitized films therethrough and provided with an exposure aperture, a second film guide spaced from-said exposure guide and provided with a light aperture through which printing light passes to said exposure aperture and adapted for the passage of a light control film therethrough, and means for feeding said printing, sensitized and control films through said guides in synchronism. characterized by a feed sprocket disposed between said guides and engaging said printing and sensitized films in said exposure guide at said exposure aperture and adapted to permit said print-- ing' light to pass between said guides 3. In a motion picture film printing machine the combination with a curved exposure guide adapted for the passage of superposed printing and sensitized films therethrough and provided with an exposure aperture on'the concave side thereof, a second curved film guide spaced from said exposure guide and extending corresponding- 1y therewith and having its concave side facing that of said exposure guide and provided with a light aperture through which printing light passes to said exposure aperture and adapted for the passage of a light control film therethrough, a feed sprocket disposed between said guides on axis normal to the curvature thereof and engaging said printing and sensitized films in said exposure guide at said exposure aperture and adapted to permit said printing light to pass between said guides, and means for feeding said light control mm through said second guide in synchronism with but at a slower speed than that of the printing and sensitized films comprising a pair of feed sprockets engaging said light control film at opposite ends of said second guide.

4. In a motion picture machine the combination with a light apertured film guide including a face guide gate movable facewise of the guide into and out of film retaining position and provided with a face disposed corresponding'with said movement of the gate and with an angled light passage continuing the light aperture of the gate and terminating in an opening at said face, a relatively stationary part provided with a face opposing said face of the gate and with a light passage terminat- -ing at its said face and continuing the adjacent portion of the light passage of said gate and a reflecting member on said gate at the angle of the light passage thereof for reflecting light from the light passage of said stationary part to the light aperture of the guide.

5. In a motion picture machine the combination with a light apertured film guide including a face guide gate pivoted for movement facewise of the guide into and out of film retaining position and provided with a face disposed normal to the pivotal axis thereof and with an angled light passage continuing the light aperture of the gate and terminating in an opening in said face, a frame on, which said gate is pivotally mounted and provided with a face opposing said face of the gate and with a light passage terminating at its said face and continuing the adjacent portion of the light passage of said gate, a reflecting member on said gate at the angle of the light passage thereof for reflecting light from the light passage of said frame part to the light aperture of the guide, and a condensing lens in the light passage of said gate between said reflecting member and the light aperture of the guide.

6. In a photographic printing machine the combination with an exposure device for printing progressively upon a sensitized photographic element from a photographic printing element, of means for feeding said sensitized and printing elements in printing relation through said exposure device in either direction, and automatic light control means for varying the printing light during the printing operation and adapted to provide the same exposure at corresponding portions of the printing element irrespective of the direction of feed of said printing and sensitized elements.

7. In a photographic printing machine the combination with an exposure device for printing progressively upon a sensitized photographic element from a photographic printing element and adapted to have the printing light thereof varied by a fed light control element progressively operative upon said light, of means for feeding said sensitized and printing elements in printing relation and said control element in controlling relation therewith in either direction.

8. In a motion picture film printing machine the combination with an exposure device for printing progressively upon a sensitized film from a printing film, of an exposure control film through which the printing light passes progressively in exposing said sensitized film by said exposure device and provided with sections of individually preselected different densities and of individually preselected extents for varying the exposure of .said sensitized film by said exposure device, and means for feeding said sensitized, printing and control films in synchronism in either direction.

9. In a motion picture film printing machine the combination with an exposure device for printing progressively upon a sensitized film from a printing film, of an exposure control film through which the printing light passes progressively in exposing said sensitized film by said exposure device and provided wtih sections of extents corresponding with sections of different densities of said printing strip and arranged correspondingly therewith and of different photographically produced densities preselected from the densities of the corresponding sections of said printing strip, and means for feeding said sensitized, printing and control films in synchronism in either direction.

10. In a motion picture film printing machine the combination with an exposure device for printing progressively upon a sensitized film from a printing film and adapted to have the printing light thereof varied by a fed light control strip progressively operative upon said light, of means for feeding said sensitized and printing films in printing relation and said control strip in controlling relation therewith in either direction, and means for automatically stopping operation of said feeding means in either direction at the end of a predetermined run thereof.

11. In a motion picture film printing machine the combination with an exposure device for printing progressively upon a sensitized film from a printing film, of means for feeding said sensitised and printing films in printin relation.

through said exposure device in either direction. automatic light control means for varying the printing light during the printing operation and adapted to provide the same exposure at corresponding portions of the printing film irrespective of the direction of feed of said films, and means for automaticalLv stopping operation of said feeding means in either direction at the end of a predetermined run thereof.

12. In a motion picture machine the combination with two constant film feed sprockets driven in unison, of a pivoted film tensioning member for tensioning a film between said sprockets, a second member pivoted correspondingly with said tensioning member, a spring operative between said tensioning device and said pivoted member for urging said tensioning member in its film tensioning direction, an engagement between said tensioning device and said pivoted memberand operative oppositely with reference to said spring, and means for -operating said pivoted member against the influence of said spring thereon and for selectively positioning the same.

18. In a motion picture machine the combination with three constant film feed sprockets driveninunison,ofapairoffilmtensioningdevices operative upon a film fed by said sprockets,.

one between the intermediate sprocket and another sprocket and the other between the intermediate sprocket and the third sprocket, and yieldablyurgedagainstthefilm, andmeansfor alternately positioning said tensioning devices in tension released positions.

14. In a motion picture film printing machine the combinationwith three constant film feed sprocketsdriveninunisomofapairoffilmtenstoning dev'ices operative upon a film fed by said sprockets, one between the intermediate sprocket and another sprocket and the other between the intermediate sprocket and the third sprocket. and yieldably urged against the film, and common means for positioning said tension devices in lacing positions and for alternately positioning the same. in tension and tension released positions.

15. In a motion picture film printing machine the combination with a constant feed exposure device operaflve upon superposed sensitized and printing films and including a constant teed sprocket means engaging said films, of two pairs of constant feed sprockets driven in unison with said sprocket means for individually feeding said films to and from said exposuredevice, of two pairs of film tensioning devices individually operative upon said films-between said sprocket means and said pairs of sprockets and yieldabiy urged against said films, and common means for simultaneously positioning said tension devices in lacing positions and for alternately positioning the tensioning devices associated with opposite yieldably urged against said films, means for operating said sprocketsasa group in either direction, means for alternately positioning the tensioning devices associated with opposite sides ofsaidexposuredeviceintensionandiension released positions to correspond with the direction of feed said films, and automatic light control means for varying the printing light during the printing operation and adapted to provide the same exposure at corresponding portions 10 of the printing film irrespective of the direction of feed of said films.

17. In a motion picture film printing machine the combination with a constant feed exposure device for printing Wvely upon a sensitized l5 filmfrom aprintingfilm disposedinsuperposed relation therewith including aconstant feed sprocket engaging said films, additional constant feed sprockets driven in unison with said first 4 mentioned sprocket for individually feeding said 90 filmstoandfromoppositesidesofsaidexposure device, film tensioning devices individually operative upon said films between said first mentioned sprocket and said additional sprockets and yieldably urged against said films, means for operat- 95 ing said sprockets as a group in either direction, means for alternately positioning the tensioning devices associated with opposite sides of said exposure device in tension and tension released positions to'correspondwith the direction of feed ofsoidfilms,andmeanswherebyanexposure control element, through which the printing light passes progressively in exposing said sensi-. tised film by said exposure device, is fed in cor.- respondence with saidffilms in either direction 3 corresponding with the direction of feed of said 18. In a motion picture machine the combination with three constant film feed sprockets driven in unison, of .a pair of tensioning devices do operative upon a film fed bysaid sprockets, one between the intermediate sprocket and another sprocket and the other between the intermediate sprocket and the third sprocket, and yleldably. urged against the film, means for alternately-po- I sitioning said tensioning devices in-tension and tension released positions, means for operating saidsprockets asa groupin eitherdirection, and means whereby said first and second mentioned means are controlled together.

19. In a motion picture machine the combination with three constant film feed sprockets driven in unison, of a pair of tension devices operative upon afilm fed by said sprockets, one between h the intermediate sprocket and another sprocket I5 and the other between the intermediate sprocket and the third sprocket; and yieldably urged against the film, means for alternately positioning said tensioning devices in tension and tension released positions including a movable element, an electric motor for driving said sprockets, a reveming switch in circuit with said motor for sides of said exposure device in tension and tenoperating the same in either-direction, and an sion released positions.

16. In a motion picture film printing machine the combination with a constant feed exposure device for px1nting progressively upon a sensi- 'tia edfilmfromaprintingfilmandincludinga constant feed sprocket means engaging said films. additional constant film feed sprockets driven in unison with said sprocket means for feeding said films to and from opposite sides of said exposure device. film tensioning devices individually operative upon said films between said sprocket means and said additional sprockets and operative connection between said movable cle ment and said switch.

20. In a motion picture film printing mschin the printing element irrespective of the direction of feed of said films, and means for automatically stopping operation of said feeding means in either direction after predetermined 11.1118 thereof.

21. In a motion picture film printing machine the combination with an exposure device for printing progressively upon a sensitized photo graphicfilmfromaprintingfilm,anexposure control element through which the printing light passesinexpomngsaid sensitizedfilminsaid exposure device and provided with sections of preselected densities and of preselected extents, means for feeding said films and said control element' as a group in correspondence in either direction, and adjustable means for automatically stopping the printing operation'in either direction of feed after predetermined runs of said films and light control element.

22. In a motion picture film printing machine the combination with an expomre device, of an upwardly disposed pair of spools for a sensitized film and a downwardly disposed pair of spools for a printing film, means for carrying and feeding saidfilmsbetweentheirspoolsandsaidexposure device in paths with that of said sensitized film above that of said printing film, means whereby said films may be fed in printing relation in either direction including means for operating eitheroi'eachpairofspoolstotakeupthefilm fed thereto, and automatic light control means for varying the printing light during the printing operation and adapted to provide the same exposure at corresponding portions of the printing film irrespective of the direction of feed of said-sensitized and printing films.

23. In a motion picture film printing machine the combination with an exposure device, of an upwardlydisposedpair ofspoolsforasensitized film and a downwardly disposed pair'of spools for aprintingfilm,athirdpairofdownwardlydisposed s'poolsgfor a light control strip operative upon theprinting light in exposing said sensitised film by said exposure device, means for carryin and feeding'said films and light control strip their spools and said exposure device inpathswiththatofsaid sensitisedfiimabove of said'printing film,

including means for operating either of each pairofspoolstotakeupthefilmorstrlpfed 24. In a motion picture film printing machine the with a picture record exposure 5 device and a sound record exposure device horisontally spaced therefrom, of an upwardly disposed pair of horizontally spaced spools for a sensitised film and two pairs of downwardly disposed horizontally spaced spools for a picture 10 record printing film and a sound record printing film, two additional pairs of downwardly disposed spools for a light control strip operative upon the printing light in exposing said sensitized film by said picture record exposure device and for a 15 second light control strip operative upon the printing li ht in exposingsaid sensitized film by said sound record exposure device, means for carrying and feeding said films and strips between their spools and said exposure devices, said sen- 2o sitized film to,said picmre record exposure device only or to both of said exposure devices and said printing films and control strips each to their related exposure devices, in paths with that of said sensitized film above those of said printing. :5 films and control strips, and means whereby said films and control strips may be fed in printing and exposure controlling relation in either direction including means for operating either of each pair of spools to take up the film or strip fed :0 thereto. 1

' 25. In a motion picture film printing machine the combination with a horizontally disposed I drive shaft, exposure devices spaced along said shaft including film guides extending correas spendin with'said shaft, feed-sprockets associated with said exposure devices and disposed normal tosaid shaft, additional feed sprockets spacedalongsaid shaftforfeedingfilmstoand from said exposure devices, spiral gearing spaced 40 along said shaft for driving said sprockets, tension devices spaced along said shaft and operasmear s. nowm 

